| title | ms.custom | ms.date | ms.prod | ms.reviewer | ms.suite | ms.technology | ms.tgt_pltfrm | ms.topic | ms.assetid | caps.latest.revision | author | ms.author | manager | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Creating AutoIncrement Columns |
03/30/2017 |
.net-framework |
|
article |
cf09732a-ab54-4d98-89e2-4d0a1f28fbce |
4 |
JennieHubbard |
jhubbard |
jhubbard |
Creating AutoIncrement Columns
To ensure unique column values, you can set the column values to increment automatically when new rows are added to the table. To create an auto-incrementing xref:System.Data.DataColumn, set the xref:System.Data.DataColumn.AutoIncrement%2A property of the column to true. The xref:System.Data.DataColumn then starts with the value defined in the xref:System.Data.DataColumn.AutoIncrementSeed%2A property, and with each row added the value of the AutoIncrement column increases by the value defined in the xref:System.Data.DataColumn.AutoIncrementStep%2A property of the column.
For AutoIncrement columns, we recommend that the xref:System.Data.DataColumn.ReadOnly%2A property of the DataColumn be set to true.
The following example demonstrates how to create a column that starts with a value of 200 and adds incrementally in steps of 3.
Dim workColumn As DataColumn = workTable.Columns.Add( _
"CustomerID", typeof(Int32))
workColumn.AutoIncrement = true
workColumn.AutoIncrementSeed = 200
workColumn.AutoIncrementStep = 3 DataColumn workColumn = workTable.Columns.Add(
"CustomerID", typeof(Int32));
workColumn.AutoIncrement = true;
workColumn.AutoIncrementSeed = 200;
workColumn.AutoIncrementStep = 3; See Also
xref:System.Data.DataColumn
DataTable Schema Definition
DataTables
ADO.NET Managed Providers and DataSet Developer Center